text: // This file is part of libigl, a simple c++ geometry processing library.
  //
  // Copyright (C) 2015 Alec Jacobson <alecjacobson@gmail.com>
  //
  // This Source Code Form is subject to the terms of the Mozilla Public License
  // v. 2.0. If a copy of the MPL was not distributed with this file, You can
  // obtain one at http://mozilla.org/MPL/2.0/.
  #include "facet_components.h"
  #include <igl/triangle_triangle_adjacency.h>
  
  #include <queue>
  template <typename DerivedF, typename DerivedC>
  IGL_INLINE void igl::facet_components(
    const Eigen::PlainObjectBase<DerivedF> & F,
    Eigen::PlainObjectBase<DerivedC> & C)
  {
    using namespace std;
    typedef typename DerivedF::Index Index;
    vector<vector<vector<Index > > > TT;
    vector<vector<vector<Index > > > TTi;
    triangle_triangle_adjacency(F,TT,TTi);
    Eigen::VectorXi counts;
    return facet_components(TT,C,counts);
  }
  
  template <
    typename TTIndex,
    typename DerivedC,
    typename Derivedcounts>
  IGL_INLINE void igl::facet_components(
    const std::vector<std::vector<std::vector<TTIndex > > > & TT,
    Eigen::PlainObjectBase<DerivedC> & C,
    Eigen::PlainObjectBase<Derivedcounts> & counts)
  {
    using namespace std;
    typedef TTIndex Index;
    const Index m = TT.size();
    C.resize(m,1);
    vector<bool> seen(m,false);
    Index id = 0;
    vector<Index> vcounts;
    for(Index g = 0;g<m;g++)
    {
      if(seen[g])
      {
        continue;
      }
      vcounts.push_back(0);
      queue<Index> Q;
      Q.push(g);
      while(!Q.empty())
      {
        const Index f = Q.front();
        Q.pop();
        if(seen[f])
        {
          continue;
        }
        seen[f] = true;
        vcounts[id]++;
        C(f,0) = id;
        // Face f's neighbor lists opposite opposite each corner
        for(const auto & c : TT[f])
        {
          // Each neighbor
          for(const auto & n : c)
          {
            if(!seen[n])
            {
              Q.push(n);
            }
          }
        }
      }
      id++;
    }
    assert((size_t) id == vcounts.size());
    const size_t ncc = vcounts.size();
    assert((size_t)C.maxCoeff()+1 == ncc);
    counts.resize(ncc,1);
    for(size_t i = 0;i<ncc;i++)
    {
      counts(i) = vcounts[i];
    }
  }
  
  #ifdef IGL_STATIC_LIBRARY
  // Explicit template instantiation
  template void igl::facet_components<long, Eigen::Matrix<long, -1, 1, 0, -1, 1>, Eigen::Matrix<long, -1, 1, 0, -1, 1> >(std::vector<std::vector<std::vector<long, std::allocator<long> >, std::allocator<std::vector<long, std::allocator<long> > > >, std::allocator<std::vector<std::vector<long, std::allocator<long> >, std::allocator<std::vector<long, std::allocator<long> > > > > > const&, Eigen::PlainObjectBase<Eigen::Matrix<long, -1, 1, 0, -1, 1> >&, Eigen::PlainObjectBase<Eigen::Matrix<long, -1, 1, 0, -1, 1> >&);
  template void igl::facet_components<int, Eigen::Matrix<int, -1, 1, 0, -1, 1>, Eigen::Matrix<int, -1, 1, 0, -1, 1> >(std::vector<std::vector<std::vector<int, std::allocator<int> >, std::allocator<std::vector<int, std::allocator<int> > > >, std::allocator<std::vector<std::vector<int, std::allocator<int> >, std::allocator<std::vector<int, std::allocator<int> > > > > > const&, Eigen::PlainObjectBase<Eigen::Matrix<int, -1, 1, 0, -1, 1> >&, Eigen::PlainObjectBase<Eigen::Matrix<int, -1, 1, 0, -1, 1> >&);
  template void igl::facet_components<Eigen::Matrix<int, -1, -1, 0, -1, -1>, Eigen::Matrix<int, -1, 1, 0, -1, 1> >(Eigen::PlainObjectBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> > const&, Eigen::PlainObjectBase<Eigen::Matrix<int, -1, 1, 0, -1, 1> >&);
  #ifdef WIN32
  template void igl::facet_components<__int64,class Eigen::Matrix<__int64,-1,1,0,-1,1>,class Eigen::Matrix<__int64,-1,1,0,-1,1> >(class std::vector<class std::vector<class std::vector<__int64,class std::allocator<__int64> >,class std::allocator<class std::vector<__int64,class std::allocator<__int64> > > >,class std::allocator<class std::vector<class std::vector<__int64,class std::allocator<__int64> >,class std::allocator<class std::vector<__int64,class std::allocator<__int64> > > > > > const &,class Eigen::PlainObjectBase<class Eigen::Matrix<__int64,-1,1,0,-1,1> > &,class Eigen::PlainObjectBase<class Eigen::Matrix<__int64,-1,1,0,-1,1> > &);
  #endif
  #endif
  